Hammer drill



bil

Patentedv Aug.4 4, 1925.

uNlTEn STATES" 1548455 PATENT OFFICE.

. GORGE E. lGIIMLAJI, '0F BOSTON, IASSACHUSETTS, ASSIGNOB T0 SULLIVAN i HACHINEBY CQMPANY, A CORPORATION 0E MASSACHUSETTS.

' HAMMER muuu.,v

.Application 'led Karen 25, 1.916,'Serial No.' 86,814. Renewed February 421,192.3.v

To all whom t may coment.'

Be it knownthat I, GEORGE H. GILMAN, a citizen of the United States, residing at Boston,in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Hammer Drills, of whichk the; following is a full, clear, and exact specification.

My invention relates to-hammer drills.

'It lhas heretofore been proposed to provide a resiliently mounted stop for' limiting the forward movement oft-he steels used in such drills, a stop of the characterreferred to being shown in. my Patent No. 1,126,628,

January 26, 1915. VIn the use of such adeL vice, however, it-has been found that when withdrawing a steel, the hammer is sometimes unable to strike the end of the steel' when the latter is in its extreme forward position, i. e.'with its shoulder or collar rest- -ing' against the stop, considerable difiiculty` having accordingly been experienced with v stuck steels.

My invention has for its object to release a stuck drill steel in an improved manner.

A more specific object of my inventionis to4 provide improved .means whereby the steel may be `maintained within the path of the hammer as the steel is Withdrawn from a hole, in such a manner that the hammer may be made to actupon the rear end of the 'steel at any time and thereby cause the dislodgement or crumbling of the substance-erlaubrom being withdrawn. In the accompanying drawings, I have for purposes of illustration shown one ein-.-

bodiment which my invention may assume in practice. e

Figure 1 is a plan view partially in section, of a hammer drill equipped with my improvement. Y

Figure 2 is anenlarged detail view of a portion of the nuechanism-shown in Figure l, the steel engaging member being shown in operative and inoperative position.

Figure 3 is an end view of the steel'en gaging member in operative position, the same being shown as seen from the lettA iu .Figures 1 and 2.,

lligure 4 is a detailview of the end ot the chuck.i

The hammer drill may be et any lmown or standard construction, so that the same preventing need not be specifically described hereinv A the cylinder 3 dis osed between the same,

- and that in this cyllnder moves a piston having preferably a reduced hammer portion 4:

movable through' a rotatable or stationary chuck 5, into enga ement with the end of the steel 6, which, o .course, .extends outward through a suitable opening 7 in theend ofi the chuck.

In my improvement, means are provided whereby the drill steel v6, while being Withdrawn from a hole, may be retained within range of the 1hammer portion 4 of the piston so that, instead of the hammer operating uselessly without striking the steel, as is the case with the stop heretofore used, when the steel is in its extreme forward position the hammer may continue to strike on the end:

of the steel. In carrying out my improvement, these means preferably cooperate with a projection or suitable annular collar 8, such, for instance, as is usually provided on a steel, and through their engagement .with that projection or collar, force the steel back into the chuck and retain it in such a position therein that it is within striking. range of the hammer. In the embodiment of my invention shown herein, the assume the vform of a yoke y9 throu h which the steel is reciprocable, the yoke sing adapted to fit over the shank of the drill a slight distance in front of the collar 8 when the latter en-` gages the chuck, and having rearwardly eatending 4arms 10 ivotally mounted on the drill and dispose-dion opposite sides of the chuck 5. As shown, these arms are'provided with lateral cylindrical extensions 11. at their rear ends, and these extensions are in turn provided with longitudinally extending op positely tapered communicating openings 12 "therein, through which extend suitable longit'udinally disposedrods 13.y These rods 13 are preferably, though not necessarily, the

side rods of the drill which extend between the front and rear heads thereof, although other suitable rods may be employed if dei sired. As shown, these rods, in turn, carry on their front ends, coiled s rings lt normally holding the yoke agamst. the collar 8 and acting between suitable nuts 15 and huders 16, the latter in Vthisinstance'preferably being provided with suitable arcu ate recesses l .having beveled de 18 se` lll@ Mld

' the rods 12 as a pivot in its movementvfrom its inoperative position shown in dotted lines in F igure`2, to its operative position shown in full lines in that iigure. Attention is also directed to the fact that the member 9 is also preferably res'iliently connected to the arms l0 thereof, through curved spring-like portions 19 preferably formed integral therewith and with the arms, and that these arms 10Vare also slightly Vresilient laterally, suitable grooves 2O (Fig. 4) or equivalent raised portions being provided on the sides of the outer chuck casing 21 so p that these arms may be snapped into position and non-positively locked against accidental displacement when the yoke is lowered to operative position.

.In the use of my improved construction, the yoke 9 may, of coursefbe thrown to its operative position whenever it is desired to operate the drill, the same not interfering with the operation of the steel when the latter is held against the work. However, in service it is usually only moved to operative position when the steel is to be withdrawn or becomes stuck in its hole. It will of course be'obvious from the above descrip' tion that when the steel is'thus wedged or stuck in its hole by any means, as for instance, by loose bits of rock or the like catching between the bit and the edge of the'hole, the hammer may be made to continue to operate upon the steel, it only being necessary to advance the drilland lower the yoke 9 from its inoperative position shown in dotted lines in Figure 2, to its operative position shown in full lines in that figure, Where the yoke is disposed outside 'but adjacent the front wall of the collar 8, in order thus to limit the forward movement of the steel 6 and thereby retain the rear or inner end of the same within the reach of the hammer 4, so that the latter, by successive blows thereon and through the cooperation of the resiliently mounted yoke, may bring about such a vibration of the steel as to dislodge or crumble the particles retarding the retraction of the steelfrom the hole. The yoke 9 may then, of course, be returned to its ins operative position and'the drilling operation be resumed when desired.

Due to my improved construction, it will be noted that when the steel becomes stuck in the hole, the inner end of the same is retained in operative relation with respect to the hammer, i. e. in such a relation with respect tothe 4hammer that the latter mayV be made 'to drivel the. steel forward and thereby, in cooperation with the; resiliently mounted -member 9, reciprocatethe steel be-A tween the limits established bythe resiliently mounted member 9 and the front end of the chuck, in such a manner as to cause a vibration of the steel sufficient to disengage the same from tlie hole. More specifically, it will be noted that due to the fact that the member 9 is normally out of engagement withvthe collar on the drill steel, hammer blows are struck both by thev hammer and the steel. in such a manner as to produce a service without breakage. f

The structure above set out also effects -broadly another result, namely, of delinitely imparting to the tool a sharply applied `striking force in a rearward direction. This result is accomplished dueto the fact that upon attempting to remove the tool the transverse portion ofthe tool retainer will engage the collar 8 so that when the hammer suddenly hitsthe steel shank, the force and energy thereof-will be transmitted to the tool retainer and thereafter immediately re turned to the steel in the form of a sharp rearwardly directed driving force, the beneticial-eil'ectof which is realized in view of the' fact that the hammer is moved, by the air admitted-to the front endof thecylinder, away from the steel instantly after the blow is .imparted to it. V

While I have in this application specilically described onel embodiment which my invention may assume in practice, it is of course to be understood that the form shown herein is shown for purposes of illustration, and that the invention may be modified and embodied in other forms without'departing from its spirit, it being my intention to include all suoli modifications within the scope of the appended claims.v

What I claim as new and desire to secure by Letters Patent is:

l. A percussive .drill including a movabley hammer and a chuck, and means carried by said drill and relative to which a steel in y said'chuck is reciprocable for retaining the inner endof the steel in operative relation with respect to said hammer.

2. A percussive drill includin a movable hammer and a chuck, and resi ient means carried by said drill and relative to whichr a steel in said chuck is reciprocable for retaining the inner end of the steel in operative relation with res ect to said hammer.

3. A percussive drill includingr a movable hammer and a chuck, and resilientl mount ed meansl carried by said drill an relative to which a steel inv'said chuckis reciprocable for retaining the inner-,end of'- the steel in operative relation with respect: to said hammer.

4. A percussive drill including a movable hammer and a chuck, and normally inoperative adjustable. means carried by said -drill and relative to which a steel in saidy y said chuck for retaining the inner end of the same in position to be operated upon by said hammer.

6. A percussive drill including a movable hammer and a chuck, a drill steel, and re- 4silientlynounted means carried by said drill and engageable' by said steel after a limited reciprocation. thereof in said chuck for retaining theinner end of said steel in position to be operated upon by said hammer.

7 A percussive drill including a hammer and a chuck, and resiliently mounted means for retaining a steel carried in said chuck in operative' relation with respect to said' hammer and cooperating therewith vibrating the steel engageable by the steel with a hammer blow after a limited reciprocation of the latter within said chuck.

8. A percussive drill including a hammer and a chuck, andmeans for retaining the inner end of a steel carried in said chuck in operative relation with respect to said hammer including a resiliently mounted yoke operatively-connected to said drill and engageableby the steel with a hammer `blow after a limited reciprocation of the latter.

9. A percussive'drill including a movable hammer and a chuck, and means -for retaining the inner end of a steel carried in said chuck in operative relation with respect to said hammer including a swinging yoke pivoted on said drill andhaving a resiliently mounted portion engageable by the steel with a hammer blow after a limited reciprocation thereof in saidl chuck.

10. A percussive drill including a hammer and a chuck, means for retaining the inner end of a steel carried in said chuck in operative relation with respect to said Ahammer including a resiliently mounted yoke operative-ly connected to said drill and engageable with a hammer blow by the steel after a limited reciprocation thereof, and means whereby said yoke may be adjusted into a plurality of positions.

1 1. A percussive drill including a movable hammer and a chuck, means for retaining the inner end of a steel carried in said chuck in operative relation with respect to said hammer including' a yoke pivoted on said drill and having a resiliently mounted portion engageable with the steel after a limited r'eciprocation thereof, and supplementary resilient means resisting movement o1- sala yoke in one direction.

12. A percussive ldrill including a mova-l ble hammer and a chuck, a steel reciprocatively carried in said chuck, and means for retaining said steel `within the range of movement of said hammer during the withdrawal of said steel from its hole including amember having a resiliently mounted steel 4 engaging portion engageable with a hammer blow by said steel after a limited reciprocation of the latter in said chuck.

13. A percussive drill including a movable hammer and a chuck, and means for retaining a steel carried in said chuck within the range of movement of said hammer during the withdrawal of the steel from its hole including a member having a steel engaging portion engageable by said steel after a limited reciprocation thereof in said chuck and resilient'p'ortions formed integral therewith and operatively connected to said drill.

14. A percussive drill including a hammer piston and a chuck, a plurality of rods on said drill, spring pressed abutments on said rods, and means for retaining the inner end of a steel carried in said chuck in operative relation with respect to said hammer including a yoke member pivotally and slidably mounted on said rods and engageable by said abutment-s, said member having a resiliently mounted portion engageable with the steel after a limited reciprocation of the latter in said chuck.

15. A percussive drill including a movable hammer and a chuck, means for retaining a steel carried in said chuck within the range of movement of said hammer during the withdrawal of the'steel from its hole including a member having a steel engaging portion cngageablc by said steel after a limited reciprocation thereof in said chuck and resilient portions formed integral therewith and operatively connected to said drill, and co-operating resilient means operating upon `said retaining means and normally resisting movement thereof in one direction. y

16. For use in combination with a drill formed with a projection adjacent the shankv end thereof, a drilling apparatus comprising a percussive motor having a cylinder` a piston reciprocablc therein with limited stroke, and a chuck for the retention of a rior t'o the movement of impact thereby the limit of travel of the a shank arranged in said chuck for actua-` tion by said piston, said drill steel having a projection. to limit its extension into saidl chuck, and a stop member cooperating with said chuck and with said projection toprevent movement of said steel shank out of the range of movement of said piston.

19. In combination with a percussive drill comprising a c linder, a piston reci rocating therein, an a chuck, a drill steel aving a shank arranged in said chuck for actuation by said piston, said drill steel havin a projection to limit its extension into sai chuck, and a stop member cooperating with saidchuck and with said projection toprevent movement of said steel shank out of the range of movement of said piston, said.

stop Abeing so located as to permit limited movement of said steel prior to. impact of said projection on said'stop.

20. In combination with a percussive drill comprising a cylinder, a piston reciprocating therein, and a chuck, a drill steel having a shank arranged in said chuck for actuation by said piston, said drillsteel havinga projection to Ylimit its extension into said chuck, and a stop member cooperating with said chuck and with said projection to pre. vent movement of said Steel shank out of the range of movement of said piston, said stop having a yoke member supported by an integral spring mounting and having a resilient connection with saiddrill.

21. A hole forming mechanism comprising a motor having a hammer piston, a tool receiving chuck, a hole forming tool insaid chuck, and means relative to which said tool is reciprocable for retaining the inner end of the tool always in operative relation to said piston.

22. A hole forming mechanism `comprising a hole forming tool and tool supporting and hammering means comprising a percussive motor whose piston is adaptedto percussively actuate the tool, and means forining a guide and support for the tool permitting limited free longitudinal movement of the-latter while preventing movement thereof to a point where it will not receive blows from the piston.

23. In combination, hammering means comprising a movable hammer, a hole forining implement pei-'cussively actuated by Said hammer, and means for supporting and ositioning said implement 'including soc ret means in which said implement is sup orted and means operative to be engaged y the implement 'after a limitedinovement thereof in said socket means and to limit the forward movement of said implement in said socket means whereby the same cannot move beyond aposition in which it receives the percussive action of said hammer. 1

24. For use in combination with a hole forming implement provided with means forming an abutment at a point remote from the forward end thereof, a tool supporting and actuating apparatus comprising a percussive motor having a cylinder, a piston reciprocable therein with limited stroke, and means forming a socket within which a portion of such a tool is received together with a'stop disposed forward of the rear end of said socket and so positioned as to cooperate with said abutment and retain' said tool with r`its rear end' within the limits of the path of travel of the percussive piston.

25. A hole forming mechanism comprisi movement, said tool being adapted to have relative longitudinal movement in opposite directions in the hole being formed, said elements constituting means whereby a hammering action is imparted to said tool in either direction of said longitudinal movement and independently of the amount of resistance offered to said movement.

A 26. A hole forming mechanism comprising a motor having a hammer piston, a hole forming tool, a tool support permitting the tool and support to have limited free relative movement, said tool being adapted to have relative longitudinal movement in opposite directions` in the hole being formed, said elements constituting means whereby hammering action isimparted to said tool while the same lis moving relatively into and out of a hole, said action being independent of the amount of resistance offered to removal.

27. A hole forming mechanism comprising a motor having a cylinder, a hammer piston therein, a hole forming tool, a tool support permitting the tool and support to have limited free relative movement, said tool being adapted to have relative longitu-V j ed to said steel to form a hole on the moving.

of said cylinder in a forward direction relative to saidholeand whereby a hammering action is also imparted to said 4tool when said cylinder is relatively rever'sely moved,

said actionbeing independent of the amount of resistance offered to said reverse movel ment.

In testimony whereoiI I aiiix mysignature. r GEORGE H. GILMAN. 

